Note: Descriptions are shown in the official language in which they were submitted.
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IMPROVED SHROUD
BACKGROUND OF THE INVENTION
(1) Field of the Invention
The present invention relates to an improved
shroud for a dual inner and outer cyclonic cleaning
-apparatus. In particular, the present invention relates to
a shroud which has a perforated section that is parallel
with and purposely spaced from the inside surface of the
outer cyclone or container and which allows air to pass
into a frusto-conically shaped inner cyclone without
plugging the inlet openings to the inner cyclone through
the apparatus.
(2) Prior ~rt
Cyclonic vacuum cleaning apparatus are shown in
my U.S. Patent Nos. 4,573,236; 4,593,429; 4,S71,772;
4,643,748; 4,826,515; 4,853,011 and 4,853,008. My U.S.
Patent No. 4,853,008 describes a dual cyclonic cleaning
apparatus wherein a combined disc and shroud unit is
mounted on the outside of the inner cyclone in order to
retain dirt in an outer cyclonic cleaner. The shroud has a
perforated lower section adjacent to and above the disc
which is parallel to the conical outside surface of the
cyclone. The perforated section acts as an air inlet to
the inner cyclone while the disc keeps large dirt particles
and fibrous matter in the outer cyclone. The combined disc
and shroud work well; however, there was a need for an
improved design which would not allow the shroud
perforations to be filled with dirt before the outer
cyclone was full of separated dirt
, 2056161
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OBJECTS
It is therefore an object of the present
invention to provide an improved cleaning apparatus wherein
the shroud is designed to substantially reduce the tendency
for dirt particles and fibrous matter to obstruct the
shroud openings leading to the inner cyclone air inlet.
Further, it is an object of the present invention to
provide a combined disc and shroud which is easily mounted
on the outside of the inner cyclone. Still further, it is
an object of the present invention to provide an improved
shroud which is simple and inexpensive to construct and
easy to clean and which at the same time prevents escape
of fibrous matter from the outer cyclone. These and other
objects will become increasingly apparent to those skilled
in the art and by reference to the drawings.
IN THE ~R~WINGS
Figure 1 is a left side perspective view of a
preferred upright type vacuum cleaning appliance of the
present invention, particularly showing an outer cyclone 15
surrounding the combined shroud and disc unit 50 mounted on
the outside of an inner cyclone 20.
Figure 2 is a front cross-sectional view along
line 2-2 of Figure 1 showing the shroud and disc unit 50
positioned between the inner cyclone 20 and the outer
cyclone 15.
Figure 2~ is a front cross-sectional view along
a plane perpendicular to line 2-2 of Figure 1 showing the
spring catch 55 for removing the outer cyclone 15 and
receiver 140 from the inner cyclone 20.
Figure 2B is a front cross-sectional view along
line 2-2 of Figure 1 showing another version of the shroud
and disc unit 150.
Figure 2C is a front cross-sectional view along
line 2-2 of Figure 1 showing another version of the shroud
~ 250.
Figure 3 is a plan cross-sectional view along
line 3-3 of Figure 2 showing the dirty air inlet passage
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27, the clean air exhaust passage 28 and the intermediate
handle 21 mounted on the outside of the outer cyclone 15.
Figure 4 is a plan cross-sectional view along
line 4-4 of Figure 2 showing the tangential air inlet into
the inner cyclone 20.
~igure 5 is a plan cross-sectional view along
line 5-5 of Figure 2 showing the perforated openings 50e
through the shroud member 50c.
Figure 6 is a separated perspective view showing
the positioning of the inner cyclone 20 inside of the
shroud and disc unit 50.
~igure 7 is a front cross-sectional view of a
preferred tank type cleaning apparatus of the present
invention and particularly showing an outer cyclone 111,
an inner cyclone 112, a dirt collection receiver 113, and
an inlet scroll 127 and associated shroud 131 to the inner
cyclone 112.
Figure 8 is a plan cross-sectional view along
line 8-8 of Figure 7 showing the inlet passage 121 to the
outer cyclone 111 with spiral member 130 for inlet into the
inner cyclone 112.
Figure 8A is a plan cross-sectional view showing
the inlet scroll 127 having two spiral members 130a and
130b rather than one as shown in Figure 8.
Figure 9 is an isometric, separated view of the
inner cyclone 112, inlet scroll 127, and the ring 132 with
openings 133.
Figure 10 is a graph showing area of openings
50e versus pressure drop across a cylindrical section 50c
of the shroud and disc unit 50.
GENER~TJ DESCR IPTION
The present invention relates to an improvement
in a cleaning apparatus including a container comprising a
bottom and a sidewall extending to and meeting the bottom,
the sidewall having an interior surface, a dirty air inlet
which is oriented for supplying dirt laden air into the
container tangentially to the interior surface of the
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container which has a circular cross-section and an air
outlet from the container; a cross-sectioned cyclone having
a longitudinal axis mounted inside the container, the
cyclone comprising a cyclone air inlet at an upper end
having a first diameter of the cyclone in air communication
with the air outlet of the container, an interior dirt
rotational surface of frusto-conical shape for receiving an
airflow from the air inlet and for maintaining its velocity
to a cone opening smaller in diameter than the diameter of
the upper end of the cyclone, the air inlet being oriented
for supplying air tangentially to the surface, an outer
surface of frusto-conical shape, and a cyclone air outlet
communicating with the interior of the cyclone adjacent the
upper end of the cyclone; a dirt collecting receiver
extending from the cone opening; and means for generating
an airflow which passes through the casing, the dirty air
inlet, the cyclone, the dirt receiver and the cyclone air
outlet, the airflow rotating around the frusto-conical ;
interior surface of the cyclone and depositing the dirt in
the receiver the improvement which comprises: a shroud
means mounted on and around the outer surface of the
cyclone, having opposed ends along the longitudinal axis
and providing an air outlet from the container into the air
inlet to the cyclone, wherein a portion of the shroud has a
cylindrical section between the ends with perforations
which allow for the flow of the air from the container to
the cyclone air inlet and which is spaced from and parallel
to the inside wall of the container and w'nerein the other
end of the shroud means is closed.
Further, the present invention relates to a
shroud means for use in a cleaning apparatus including a
container comprising a bottom and a sidewall extending to
and meeting the bottom, the sidewall having an interior
surface, a dirty air inlet which is oriented for supplying
dirt laden air into the container tangentially to the
interior surface of the container which has a circular
cross-section and an air outlet from the container; a
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circular cross-sectioned cyclone having a longitudinal axis
mounted inside the container, the cyclone comprising a
cyclone air inlet at an upper end having a first diameter
of the cyclone in air communication with the air outlet of
the container, an interior dirt rotational surface of
frusto-conical shape for receiving an airflow from the air
inlet and for maintaining its velocity to a cone opening
smaller in diameter than the diameter of the upper end of
the cyclone, the air inlet being oriented for supplying air
tangentially to the surface, an outer surface of
frusto-conical shape, and a cyclone air outlet
communicating with the interior of the cyclone adjacent the
upper end of the cyclone; a dirt collecting receiver
extending from the cone opening; and means for generating
lS an airflow which passes sequentially through the dirty air
inlet, the container, the cyclone air inlet, the cyclone,
the dirt receiver and the cyclone air outlet, the airflow
rotating around the frusto-conical interior surface of the
cyclone and depositing the dirt in the dirt receiver the
improvement which comprises: a shroud means to be mounted
on and around the outer surface of the cyclone, having
opposed ends along the longitudinal axis and providing an
air outlet from the container into the air inlet to the
cyclone, wherein a portion of the shroud has a cylindrical
section wit'n perforations which allow for the flow of the
air from the container to the cyclone inlet and which is
spaced from and parallel to the inside wall of the
container and wherein the cylindrical section is joined to
a web section an inside edge of which contacts the outside
wall of t'ne cyclone and an outside edge of which is joined
to the cylindrical section.
It is unexpected that the perforated section
could be directly facing the parallel inside wall of the
container and have a relatively close spacing of 0.6 inches
to l.4 inches (l.5 cm to 3.6 cm) to the inside wall and
still be so effective in dirt separation. For upright
vacuum cleaners as shown in Figures l and 2, the preferred
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diameter of the cylindrical section of the wall of the
shroud and the diameter of the inside surface of the
container is about 4.3 inches and 6.4 inches (10.9 and 16.3
cm), respectively. For tank type vacuum cleaners as shown
in Figure 7, the diameter of the cylindrical section of the
wall of the shroud and the diameter of the inside surface
of the container is about 8.2 inches and 10.6 inches (20.8
cm and 26.9 cm), respectively.
It was found that as low a pressure drop as
possible through the shroud is preferred. This means that
a large number of openings, preferably round, should be
provided in the perforated section of the shroud.
SPEC IF IC D~SCR IPTION
FIGS. 1 and 2 show an upright type vacuum
cleaning apparatus 10 w'nich is adapted for use in both the
vertical mode and the horizontal mode, the vertical mode
being illustrated. The functioning of the appliance will
be described with reference to this vertical mode. The
cleaning appliance 10 includes a cleaning head 11 connected
to a casing 12 which supports a motor fan unit (not shown)
that is mounted behind conventional floor engaging brushes
(not shown) and inside wheels (not shown). ~xterior wheels
13 are mounted behind the casing 12.
~n outer cyclone or container 15 is mounted on
the casing 12. The outer cyclone 15 is preferably made of
clear plastic so that a person can see the outer cyclone 15
fill with dirt. The outer cyclone 15 has a circular
cross-section along a longitudinal axis a-a and more
preferably is cylindrical, or it can be outward tapering if
space and dimensions permit. ~ skirt 16 is mounted on the
outer cyclone 15 and extends to the casing 12. The outer
cyclone 15 has a bottom wall formed by the frusto-conical-
section 40d of a receiver 40 that tapers downwardly and
outwardly from the axis a-a, and a cylindrical inner
surface 15a (Figure 3) which extends from the bottom wall
40d of the receiver 40. Supported on the outer cyclone 15
is a circular cross-sectioned airflow directing head 18
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that is sealed to the end surface of the outer cyclone 15
by a flexible inverted TJ-shaped seal 19 and an annular lip
member 15c of the outer cyclone 15 (Figure 2). Positioned
radially inward from the outer cyclone 15 and head 18 is an
inner cyclone 20. The outer cyclone 15 and the inner
cyclone 20 are preferably relatively long and slender along
the longitudinal axis a-a.
The casing 12 is provided with a vertical
extension 12a (Figure 3) which forms a rigid socket for
slideably receiving the lower end of a tubular pipe or wand
21. The pipe 21 includes a grip 22. When the pipe 21 is
fitted in the extension 12a, the hand grip 22 enables the
appliance to be used as an upright type machine. In
contrast, when the pipe 21 is slideably removed from the
extension 12a the pipe 21 is then used as a cleaner head at
the end of a flexible hose (not shown) thus converting the
appliance into a cylinder type machine. The conversion of
the appliance from one mode of operation to the other and
vice versa is described more fully in my U.S. Patent No.
4,377,882.
~ositioned adjacent to the outside wall 15b of
the outer cyclone 15 and mounting the outside wall 18a of
the head 18 on opposed sides of pipe 21 are spaced apart
dirty air inlet and clean air exhaust passages 27 and 28,
respectively. The lower half of dirty air inlet passage 27
is formed by a rigid tube 29 adjacent to the outside wall
15b of the outer cyclone 15, as shown in Figure 1. Tube 29
extends from a dirty air inlet passage (not shown) in
casing 12 to a tube 30 mounted on the outside wall 18a of
the head 18 which forms the upper half of dirty air inlet
passage 27, (Figure 3). Tube 30 communicates through the
upper part of the outside wall 18a of the head 18 through
inlet passage 31 so as to make a tangential entry and set
up a swirling, cyclonic flow of air in passage 32 of the
head 18 leading to the outer cyclone 15.
~s shown in Figure 2, depending from the circular
plate 18b of head 18 is conduit 18c which forms a clean air
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exhaust passage 33 from the inner cyclone 20. ~xhaust
passage 33 is in communication through head 18 with the
upper half of clean air exhaust passage 28 (Figure 3) which
is formed by tube 34 mounted on the outside wall 18a of the
head 18. The lower part of tube 34 leads to a rigid lower
exhaust tube (not shown) which is mounted on the outside
wall 15b of the outer cyclone 15. The lower exhaust tube
(not shown) -Eorms the lower half of clean air exhaust
passage 28 and connects to a clean air exhaust outlet (not
shown) in the casing 12 which cools the motor fan unit and
exhausts at casing vents 12b below skirt 16 as shown in
Figure 1.
The inner cyclone 20 has a frusto-conical body
extending radially downwardly and inwardly to the axis a-a
and an inlet scroll 36. The inner cyclone 20 comprises an
inner wall 20a leading to a cone opening 20b and an outer
surface 20c of the inner wall 20a. The inlet scroll 36
comprises a horizontal web 37 (Figuré 6) which extends from
the upper end surface 20d of the inner cyclone 20 to the
inner surface 18d of the head 18. ~ sleeve 38 extends
through the majority of its length from the junction of the
upper end surface 20d of the inner cyclone 20 and web 37 to
the bottom side of plate 18b. ~ second horizontal web 39
extends from the upper end 38a of sleeve 38 to the junction
where the inside wall 18d of head 18 meets plate 18b.
portion 38b (Figure 4) of sleeve 38 extends in the form of
a spiral, from the junction of the upper end surface 20d of
the inner cyclone 20 and the web 37 to the inside wall 18d
of the head 18 thereby cornpleting the inlet scroll 36 and
providing a tangential entry to the inner cyclone 20 in
order to be capable of setting up a swirling cyclonic flow
of air.
The cone opening 20b of the inner cyclone 20 is
connected to a dirt collecting receiver 40 for collecting
dirt from the inner cyclone 20. The lower end of the
outer surface 20c the inner cyclone 20 engages a circular
plate 40a which meets a frusto-conical member 40b that
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tapers downwardly and outwardly from the axis a-a. The
lower edge of frusto-conical member 40b meets the upper
edge of a short cylindrical member 40c of the receiver 40.
Interposed between the inner cyclone 20 and the plate 40a
of receiver 40 is a flexible annular sealing member 41.
~epending from the bottom edge of the cylindrical member
40c is the frusto-conical section 40d which forms the
bottom wall of the outer cyclone 15 and which extends
downwardly and outwardly from the axis a-a to the inner
surface 15a of outer cyclone 15 about 1.1 inches (2.7 cm)
above the bottom wall 40e of receiver 40. The diameter of
the cone opening 20b is preferably at least three times the
diameter of frusto-conical section 40d, as described in
U.S. Patent No. 4,826,515.
Figure 2~ shows another preferred version of the
connection between the cone opening 20b of the inner
cyclone 20 and a receiver 140 which is similar to receiver
40. The receiver 140 is formed of a frusto-conical section
140a secured directly to the cone opening 20b through
inverted U-shaped annular seal 141a. The frusto-conical
section 140a tapers downwardly and outwardly from the axis
b-b to an inner annular ring member 140b. A bottom plate
140c, circular in plan view, extends to and meets a first
frusto-conical member 140d which tapers upwardly and
outwardly from the axis b-b. The upper edge of the first
frusto-conical member 140d meets a first cylindrical member
140e which extends to and meets a second frusto-conical
member 140f. The second frusto-conical member 140f tapers
upwardly and outwardly from the axis b-b to a second
cylindrical member 140g. The second cylindrical member
140g seals against the inner surface 16a of skirt 16
through annular ring seal 141b. The receiver 140 is
completed by annular ring seal 141c which is disposed
between the inner annular ring member 140b and the second
cylindrical member 140g thereby sealing the outer cyclone
15 from the receiver 140.
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A combined shroud and disc unit 50 is mounted
intermediate the passage 32 leading to inlet scroll 36 and
the cone opening 20b as particularly shown in Figure 2.
The upper part of the unit 50 is tapered with wall 50a
preferably parallel to the outer surface 20c of the inner
cyclone 20 and forming passage 52. The wall 50a ends in a
flange 50b which surrounds and encloses the inlet passage
32 to the inner cyclone 20. Cylindrical section 50c
depends from the lower end of wall 50a to an annular web
50d. ~ plurality of openings 50e (partially shown in
Figure 5) that are in and around the circumference of the
cylindrical section 50c, serve as an outlet from the outer
cyclone 15 to passage 51 leading to passage 52. Web 50d
extends between the cylindrical section 50c and the outer
surface 20c of the inner cyclone 20 where it meets conical
member 50f leading to a cylindrical section 50g.
~epending from the cylindrical section 50g is a disc 50h
which can be conically shaped with a large downwardly
tapered portion 50i facing the bottom wall 40d of the outer
cyclone 15. The disc 50h can have a downwardly inclined
angle alpha between about 97-1/2 to 110 from the axis a-a
or 7-1/2 to 20 from a line perpendicular to the axis a-a.
The disc 50h can also be perpendicular to the axis a-a (not
shown).
Figure 2~ shows another version of the combined
shroud and disc unit 150 that fits over the outer surface
20c of the inner cyclone 20, inside of head 18 and the
outer cyclone 15, similar to the shroud and disc unit 50
shown in Figure 2. The upper part of the unit 150 if
formed by a frusto-conical section 150a that tapers
upwardly and outwardly from the axis e-e to a flange 150b.
cylindrical section 150c depends from the lower end of
the frusto-conical section 150a to an annular web 150d.
plurality of openings 150e that are in and around the
circumference of the cylindrical section 150c, serve as an
outlet from the outer cyclone 15. Web 150d extends between
the cylindrical member 150c toward the axis e-e and
I 20~6161
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contacts the outer surface 20c of the inner cyclone 20.
Web 150d meets a conical member 150f that toget'ner with web
150d forms a seal between the inner cyclone 20 and the
lower end of the combined shroud and disc unit 150.
~xtending from the junction of the cylindrical member 150c
and the web 150d is a disc 150h which can be conically
shaped with a large downwardly tapered portion 150i. The
disc 150h can have a downwardly inclined angle alpha
between about 97-1/2 to 110 from the axis e-e or 7-1/2
to 20 from a line perpendicular to the axis e-e. The disc
150h can also be perpendicular to the axis e-e (not shown).
Figure 2C shows still another version of the
shroud unit 250 that fits over the outer surface 20c of
the inner cyclone 20, inside of head 18 and the
outer cyclone 15, similar to the shroud and disc unit 50
shown in Figure 2. The upper part of -the unit 250 is
formed by a frusto-conical section 250a that tapers
upwardly and outwardly from the axis f-f to a flange 250b.
~ cylindrical section 250c depends from the lower end of
the frusto-conical section 250a to an annular web 250d.
plurality of openings 250e that are in and around the
circumference of the section 250c, serve as an outlet from
the outer cyclone 15. Web 250d extends between the
cylindrical member 250c toward the axis f-f where it
contacts the outer surface 20c of the inner cyclone 20
similar to web 150d of the shroud and disc unit 150 in
Figure 2B. Web 250d meets a conical member 250f that
together with web 250d forms a seal between the inner
cyclone 20 and the lower end of the combined shroud and
disc unit 150. The combined shroud and disc unit 250 does
not have a disc to 'nelp keep large dirt particles and
fibrous matter in the outer cyclone 15 as is characteristic
of the shroud and disc unit 50 in Figure 2 and the shroud
and disc unit 150 in Figure 2B.
In operation of the preferred version of the
upright type vacuum cleaning apparatus 10 as shown in
Figure 2, the fan unit in casing 12 pulls air into dirty
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~_ -12-
air inlet passage 27 through tubes 29 and 30 and into inlet
passage 31 leading to the outer cyclone 15. The air
cyclones down and around the inner surface 15a and bottom
wall 40d of outer cyclone 15, over the outside of walls
40c, 40b and 40a of the receiver 40 and up the outer
surface 20c of the inner cyclone 20, then over the disc
50h, through openings 50e and up passages 51 and 52 defined
by the shroud 50 and the outer surface 20c of the inner
cyclone 20. The air then moves into passage 32 before
entering the inlet scroll 36 leading to the inner cyclone
20 where the air cyclones down the inner wall 20a to the
cone opening 20b before moving upward to the exhaust
passage 33 formed by conduit 18c. The air finally moves to
the clean air exhaust passage 28 defined by tube 34 and a
lower exhaust tube (not shown) adjacent to the outside wall
15b of the outer cyclone 15 before exhausting to the
atmosphere or to the motor fan unit in the casing 12. The
dirt collects on the bottom wall 40d of the outer cyclone
15 and on the bottom wall 40e of the receiver 40 as shown
in Figure 2. Finer dirt collects primarily in the receiver
40.
It was surprising that the openings 50e in the
cylindrical section 50c (Figure 2) could be positioned
closely adjacent to the inner surface 15a of the outer
cyclone 15. During testing, it had been thought that the
cylindrical section 50c should be as distant as possible
from the dirt swirling around the inner surface 15a of the
outer cyclone 15. It had been felt that a large distance
between the cylindrical section 50c and the inner surface
15a of the outer cyclone 15 would make it difficult for
dirt, fluff or fibrous material to become caught up in the
airflow exiting the outer cyclone 15 through the
openings50e in cylindrical section 50c. However, with the
cylindrical section 50c set as far away as possible from
the inner surface 15a of the outer cyclone 15, fluff and
fibrous material became trapped on the outer surface 50k of
the cylindrical section 50c. Surprising, it was found that
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by positioning the cylindrical section 50c closely adjacent
to the inner surface 15a of the outer cyclone that the
outer surface 50k of the cylindrical section 50c did not
attract fibrous material and that dirt did not pass
directly from the airflow circulating around the inner
surface 15a of the outer cyclone 15 to the openings 50e in
cylindrical member 50c. In fact, the outer surface 50k of
the cylindrical member 50c was apparently being wiped clean
by the airflow circulating around the inner surface 15a of
the outer cyclone 15. With this construction, the dirt can
accumulate to a relatively high level in the outer cyclone
15 (about level L) with good separation of the dirt.
As shown in Figure 2A, the outer cyclone 15 and
receiver 40 (not shown) or receiver 140 are removable from
the head 18 for emptying by releasing a spring catch 55
housed within the skirt 16. The catch 55 comprises a
central spring arm member 55a that attaches at its proximal
end 55b to the bottom surface 140h of the bottom plate 140c
of the receiver 140 through mounting bracket 140i. The
distal end 55c of the spring arm 55a forms into a first
inverted U-shaped member 55d. The spring arm 55a and
a proximal leg 55e of the first inverted U-shaped member
55d form a U-shaped junction 55f that secures~in a mating
locking member 12c mounted on the casing 12. A distal leg
55g of the first inverted U-shaped member 55d acts as a
finger grip that protrudes out from underneath the skirt 16
adjacent to the casing 12. A second inverted U-shaped
guide member 140j is mounted on the bottom surface 140h of
the bottom plate 140c of the receiver 140 spaced apart from
mounting bracket 140i and adjacent to the apex of the first
inverted U-shaped member 55d. The second inverted U-shaped
member 140j serves as a guide for an arrow tab 55h
extending from the first inverted U-shaped member 55d of
the catch 55 which helps to secure the receiver 140 and
outer cyclone 15 to the head 18 and the inner cyclone 20
when the vacuum cleaning apparatus 10 is being used.
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When the outer cyclone 15 and receiver 140 become
full of accumulated dirt, the operator lifts up on the
distal leg 55g of the first inverted U-shaped member 55d
which releases the junction 55f of catch 55 from the
locking member 12c and the arrow tab 55h from the second
inverted U-shaped member 140j. The operator then pulls the
outer cyclone 15, receiver 140 and skirt 16 away from the
handle 21 (Figure 1) which causes the annular lip member
15c of the outer cyclone 15 to release from the head 18 at
the flexible inverted ~-shaped seal 19 and the receiver 140
to release from the inner cyclone 20 at the annular seal
141a, thereby exposing the rigid tube 29, the rigid lower
exhaust tube (not shown) and the bottom part of the
intermediate pipe 21. The outer cyclone 15 and receiver
140 can then be emptied and replaced into the vacuum
cleaning apparatus 10 by fitting annular lip member 15c of
the outer cyclone 15 inside of the flexible inverted
~-shaped seal 19 and by fitting annular seal 141a around
the cone opening 20b of the inner cyclone 20. The operator
then pushes the outer cyclone 15 and receiver 140 towards
the pipe 21 until the junction 55f of catch 55 locks into
locking member 12c of casing 12 and arrow tab 55h secures
into U-shaped member 140j.
~igure 7 shows a tank type vacuum cleaning
apparatus 110, which comprises an outer cyclone 111, around
an inner cyclone 112, a dirt collection receiver 113 and a
motor driven fan unit 114. The inner and outer cyclones
111 and 112 have circular cross-sections along a
longitudinal axis c-c. The outer cyclone 111 has a base
llla and a cylindrical inner surface lllb which extends
from the outer periphery of the base llla. ~ circular
cross-sectioned flange lllc extends radially outwardly from
the upper end part of the outside wall llld of the outer
cyclone 111 and serves as one-half of a seal for the
outer cyclone 111.
~ removable cover 115 with hemispherical outer
surface 115a fits over the top of the outer cyclone 111.
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The lower edge of the outer surface 115a of cover 115 has
an annular rim 115b with a depending lip 115c which serves
as a hand grip for removing the cover 115 from the outer
cyclone 111. Extending inward from rim 115b toward the
axis a-a is a horizontal support web 115d which meets the
upper edge of a right angle cross-sectioned protrusion 115e.
~n annular gasket 116 is mounted intermediate the
protrusion 115e and the rim 115b on web 115d so as to be in
contact with the circular cross-sectioned flange lllc. The
gasket 116 serves to seal the cover 115 to the outer
cyclone 111 while the apparatus 110 is in operation. The
lower edge of the protrusion 115e meets the top edge of a
frusto-conical section 115f which tapers radially inwardly
and downwardly toward the axis c-c. ~n annular ring member
115g depends from the distal end of the conical section
115f and has openings 115h for bolts 117. Openings 115i
are provided on the hemispherical outer surface 115a which
serve as an exhaust port for the motor fan unit 114.
~ cylindrical dirty air inlet passage 118
communicates through the upper part of the outside wall
llld of the outer cyclone 111. The end part 118a of the
dirty air inlet passage 118, remote from the outer cyclone
111, is joined by a flexible tube (not shown) to a cleaner
head (not shown) for contacting a dirty surface. Flanged
section 118b of inlet passage 118, adjacent to the outside
wall llld of the outer cyclone 111, has openings 119 for
bolts 120 to secure the inlet passage 118 to the outside
wall llld of the outer cyclone 111. Inlet passage 118
leads to a dirty air inlet passage 121. ~s long as inlet
passage 121 communicates through the upper part of the
outside wall llld of the outer cyclone 111 so as to make a
tangential entry and to set up a swirling, cyclonic flow of
air in the outer cyclone 111, the exact position of the
inlet passage 121 around the circumference of the outer
cyclone 111 is not critical.
A plate 124, circular in plan view, with
dependent tube 125 centered around the axis c-c is
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positioned above the inner cyclone 112. The dependent tube
125 extends downwardly along axis c-c from the plate 124
substantially coaxially with the inner cyclone 112. The
motor driven fan unit 114 is located on the plate 124 and
is arranged so as to draw air from the inner cyclone 112
through dependent tube 125. Extending from the top side
124a of the plate 124 is annular ring member 124b which is
outside of and adjacent to the depending ring member 115g.
~nnular ring 124b has openings 126, centered on the axis
d-d coinciding with the openings 115h in the depending ring
member 115g, which enables bolts 117 to secure the cover
115 to the plate 124.
The inner cyclone 112 has a frusto-conical body
extending radially downwardly and inwardly towards the axis
c-c and a dependent inlet scroll 127. The inner cyclone
112 comprises a frusto-conical inner surface 112a leading
to a cone opening 112b and an outside wall 112c. The inlet
scroll 127 comprises the sleeve 123 which depends from the
plate 124 to a horizontal annular web 128 (Figures 7 and 8).
The web 128 extends between the upper end 112d of the
frusto-conical body and the lower end part of sleeve 123.
A second dependent sleeve 129 extends between the cover 124
and the junction of the upper end 112d of the
frusto-conical body and the web 128. The second sleeve 129
is located radially inwardly of the tubular sleeve 123 and
through the majority of its length sleeve 129 extends from
the upper end 112d of the frusto-conical body where the
upper end 112d joins the inner periphery of the web 128.
~s shown in Figure 8, a portion 130 of the second sleeve
129 extends, in the form of a spiral, from the junction of
the upper end 112d of the frusto-conica~ body and the web
128 to the tubular sleeve 123 thereby completing the inlet
scroll 127 and providing a tangential entry to the inner
cyclone 112 in order to be capable of setting up a swirling
cyclonic flow of air.
Figure 8~ shows another version of the inlet
scroll 127 where two diametrically opposed sections 130a
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and 130b extend from the junction of the upper end 112d of
the frusto-conical body and the web 128 to the tubular
sleeve 123. In this manner, the inner cyclone 112 is
provided with two opposed tangential entry points which are
capable of setting up a swirling, cyclonic flow of air. It
should be noted, that the inlet scroll 127 can be completed
by any number of sections 130 spiraling radially outwardly
from the sleeve 129 to the tubular sleeve 123 as long as
the sections 130 create a tangential entry point to the
inner cyclone 112.
~epending from the scroll 127 and spaced from the
outside wall 112c of the inner cyclone 112 is a shroud 131
which comprises of tubular ring 132 that depends from the
junction of the tubular sleeve 123 and the web 128. The
ring 132 of shroud 131 is totally perforated with a
plurality of openings 133 (partially shown in Figure 9)
that serve as an air outlet from the outer cyclone 111 to
scroll 127 leading into the inner cyclone 112. The tubular
ring 132 is parallel to and purposely spaced from the inner
surface lllb of the outer cyclone 111. The shroud 131 is
completed by a web 134 that extends between the lower end
portion of ring 132 and the outside wall 112c of the inner
cyclone 112 and a cylindrical support member 135 that
depends from the outside wall 112c of the inner cyclone 112
and which with the upper surface 134a of the web 134 forms
a right angle closure from the outer cyclone 111 at an
intermediate seal 136.
The dirt collection receiver 113 for the inner
cyclone 112 comprises a cylindrical portion 113a which
meets the upper edge of a frusto-conical section 113b
extending downwardly and outwardly from the axis c-c to the
base llla of outer cyclone 111. ~djacent to and radially
inward from frusto-conical section 113b is an annular ring
member llle of the outer cyclone 111 which extends beyond
the upper edge of frusto-conical section 113b adjacent to
the inside wall 113c of the receiver 113, thus forming a
seal between the receiver 113 and the outer cyclone 111.
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The cylindrical portion 113a is intermediate the inner
surface lllb of the outer cyclone 111 and the outside wall
112c of the inner cyclone 112 and is below the web 134 of
the shroud 131. The receiver 113 is completed by a rubber
seal 137 that extends from the top of the cylindrical
portion 113a to the outside wall 112c of the inner cyclone
112 adjacent to the web 134. In another embodiment (not
shown), cylindrical portion 113a can meet and seal against
the web 134 of the shroud 131.
The following are parameters for the preferred
vacuum cleaner:
1. Number of Holes in Shroud
In the preferred version of the uprig'nt type
vacuum cleaning apparatus 10, as shown in Figure 2, and the
preferred version of the tank type vacuum cleaning
apparatus 110 as shown in Figure 7, there should be
approximately the number and size of openings or holes 50e
in the cylindrical section 50c of the shroud and disc unit
50 and openings 133 in the tubular ring 132 shroud 131 to
position the pressure between the inner surface 50j and the
outer surface 50k of the cylindrical section 50c and to
position the pressure through the ring 132 of shroud 131 as
far along from the pressure increase rise of the graph
(Figure 10) as possible. It was found that if there was a
high differential pressure through the cylindrical section
50c and through the ring 132 of shroud 131 that large dirt
particles that collect in the outer cyclones 15 and 111
when the dirt level in the outer cyclones 15 and lll is
below level ~, will be pulled through the openings 50e in
cylindrical section 50c and the openings 133 in the tubular
ring 132 of shrou~ 131 where they will then enter the inner
cyclones 20 and 112. The high differential pressure
probably causes large particles and fluff to attach to and
block the openings 50e in the cylindrical section 50c of
the shroud and disc unit 50 and the openings 133 in the
tubular ring 132 of shroud 131. This result is undesirable
because the large dirt particles will not separate out in
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the inner cyclones 20 and 112. Instead, the large dirt
particles will be expelled out the exhaust passage 33 of
the inner cyclone 20 and through dependent tube 125
exhausting from the inner cyclone 112 where the large dirt
particles will then be drawn into the motor fan units 14
and 114. T'nis will damage the motor fan units 14 and 114
and can also result in dirt being expelled into the
atmosphere.
The above discussion is also applicable for the
pressure between the inside surface 150j and the outside
surface 150k of the cylindrical section 150c (Figure 2B)
and for the pressure between the inside surface 250j and
the outside surface 250k of the cylindrical section 250c
~Figure 2C).
The circumference of the cylindrical section 50c
of shroud and disc unit 50 in Figure 2 was 13.6 inches
(34.5 cm), the diameter was 4.3 inches (10.9 cm), and the
height was ~.6 inches (6.6 cm). Where there were
approximately 58 holes per row, a combination lying in the
range of 32 to 38 rows of holes of 2.2 mm diameter were
found to be best for the cylindrical section 50c of the
shroud and disc unit 50 of the cleaning apparatus 10 shown
in Figures 1 and 2. ~lso, the circumference of the ring
132 of the shroud 131 of t'ne tank type vacuum cleaning
apparatus 110 shown in Figure 7 was 15.5 inches (~4.8 cm),
the diameter was 8.2 inches (20.8 cm), and the height was
2.5 inches (6.4 cm). Where there were approximately 208
holes per row, a combination lying on the range of 34 to 38
rows of holes of 2.2 mm diameter were found to be best for
the ring 132 of the shroud 131. ~ 2.2 mm diameter hole is
sufficiently small to block the passage of particles of a
greater size than would be successfully separated by the
inner cyclone 20 of Figure 2 and the inner cyclone 112 of
Figure 7.
It was believed that the greater the total area
of holes 50e and 133 the less pressure there would be at
each hole. This is beneficial because the cylindrical
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section 50c and the ring 132 of the shroud 131 would be
better at not attracting fluff. ~lso, a lower pressure at
each opening 50e of the upright type vacuum cleaning
apparatus 10 and at each opening 133 of the ring 132 of the
shroud 131 of the tank type vacuum cleaning apparatus 110
would make it easier for fine dirt to gather at and maybe
block rather than be drawn through the openings 50e and
133, thereby signalling the operator that it is time to
empty the respective vacuum cleaners 10 and 110.
2. Thickness of Material for the Shroud
It was found that better results were obtained
when material at least 2 mm thick was used for the shrouds
50 and 131 . Material 1 mm thick did not work as well. It
was assumed that the thicker material causes a sharper
change in direction for the clean air and therefore
contributes to a better separation than is achieved by the
thinner material.
3. ~istance Between the Shroud and the Inner Surface of
the Outer Cyclone
For the upright type vacuum cleaner 10 in Figure
1 and 2, the distance range between the cylindrical section
50c of the shroud and disc unit 50 and the inner surface
15a of the outer cyclone 15 is preferably between 0.59
inches to 1.18 inches (1.5 cm to 3.0 cm). For the tank
type vacuum cleaning apparatus 110 in Figure 7, the
distance range between the ring 132 of the shroud 131 and
the inner surface lllb of the outer cyclone 111 is
preferably between 0.75 inches to 1.26 inches (1.9 cm to
3.2 cm). However, if the distance between the cylindrical
section 50c of the shroud and disc unit 50 is too close,
fluff will bridge between the disc 50b and the inner
surface 15a of the outer cyclone 15. ~lternatively, if the
distance is too great, fluff attaches to the cylindrical
section 50c and blocks the openings 50e. The exact
distances is dependent on the diameter of the outer cyclone
and the inner cyclone of the respective vacuum cleaning
apparatus 10 and 110.
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lt is intended that the foregoing description be
only illustrative of the present invention and that the
present invention be limited only to the hereinafter
appended claims.
